Ammonia is a waste product formed during protein metabolism.

Normally, the liver converts ammonia into urea, which is excreted in urine.

Elevated blood ammonia levels indicate impaired liver function or urea cycle disorders.

Clinical uses include:

Diagnosing hepatic encephalopathy in patients with liver disease.

Evaluating severe liver dysfunction (cirrhosis, acute liver failure).

Detecting urea cycle enzyme deficiencies (rare genetic disorders).

Monitoring patients with suspected metabolic or neurological complications.

The test is performed using a blood sample, collected and processed quickly to avoid false elevations.

Analyte: Ammonia concentration in plasma.

Normal Range: ~15 – 45 µmol/L (varies slightly by lab).

Abnormal Findings:

High ammonia: Suggests liver failure, cirrhosis, Reye’s syndrome, urea cycle disorders, or GI bleeding.

Low ammonia: Rare, usually not clinically significant.

Clinical Use:

Provides a marker for liver detoxification capacity.

Helps confirm causes of altered mental status in liver disease patients.

Guides treatment decisions in metabolic and hepatic disorders.